Faulty Bosch WWF2000 washing machine: 'pre-wash' flashes

[BillySilly]

Hi
My Bosch WFF2000 washing machine, model M515-M5100B0GB DVGWM624, is playing up.
If I move the right hand 'start time selector' knob to the programme start position either
1
the dial moves round all the way to the spin position accompanied by lots of clicks and whirrs. No water enters and no wash or rinse occurs. It is as if a relay has stuck open/closed,
or
2
It fills with water and then pumps it all out before again moving round to the start position.
Once when I moved the programme selector to the X position which is used to cancel an incorrect programme, on next starting up the dial moved to main wash and the machine did a complete wash cycle but without doing a spin.
In each case at some time the pre-wash light will blink so this must be part of the reason for the malfunction.
If you turn the dial to spin - it does.
The manual lists what you should check if the pre-wash light blinks, but all OK. We don't use the pre-wash
I could fit a part if I knew what is needed!

 

[BillySilly]

Not getting any reply, I suspected there mighy be a problem with the water level pressure switch because of a fault I once had with a Servis wm.
I pulled the thin rubber air hose off the pressure switch (the circular component that determines the correct water level in the drum, about 8cm in diameter on the rhs under the top cover) and blew down the pipe to clear a possible blockage. Next time the wm did a complete cycle. I hope it will work next time too!

 

[lesleypb]

Hi,
I know this one was a while ago, but my machine is behaving in a similar way and I wondered if the treatment had suceeded? Thanks!

 

[BillySilly]

Hello Lesleypb
Unfortunately no, but read on...

When the problem reappeared I took the back off and removed the large filter where the waste comes out. Slightly tricky to get it out but the clips are rather clever; as I recall one slides over, the other does something else which I can't remember. The filter was full of gunge. It is difficult to clean out but leaving it to soak in concentrated soda overnight I got it as new.
I then removed the plastic box at the bottom of the rear. This is where the pressure sensor pipe goes to. I found this was blocked and more importantly the hole in the bottom of the drum that it fits in was nearly completely blocked so blowing down the pipe isn't enough. Cleaned all this out and reassembled and the machine has run perfectly ever since. Total cost zilch! Total saving £400! Just a pair of dirty hands.
Good luck!

 

[lesleypb]

Billy, thanks very much - that's me occupied this evening!

 

[woody686]

Many thanks Billy. You saved me a lot of money at the weekend with this info, although I did cheat and used very hot water and a lot of shaking rather than overnight in soda.